影响沉积物中有孔虫丰度的死态因素探讨

POSTMORTEMOLOGICAL FACTORS RESPONSIBLE FOR FORAMINIFERAL ABUNDANCE IN SEDIMENT

根据近年野外调查和室内研究，本文探讨了影响沉积物中有孔虫丰度值的诸死态因素，死态因素乃指环境对死亡后的生物体产生各种变化作用的自然因素。研究表明溶解作用和搬运作用对沉积中有孔虫丰度有极为重要的影响作用。同时，沉积作用和成岩作用也是不容忽视的影响因素。充分考虑这些因素。

Based on coastal core and surface sample analyses and laboratory experiment,various postmortemological factors are evaluated for the foraminiferal abundance in sediment .Postmortemological factors are the environmental agents that affect foraminiferal test after the organism dies.The potential postmortemological factors responsible for the foraminiferal abundance in sediment are decomposition of protoplasm,transport and dissolution of tests,sedimentation rate,halmyrolysis,diagenesis,anadiagenesis and epidiagenesis.Decomposition of protoplasm may acidify the microenvironment of the test and cause dissolution.Transport plays an important role in either increasing or decreasing abundance .Test dissolution is also important to the preservation of test and foraminiferal abundance.Dissolution experiment indicates that different water media,different taxa and different test size have different dissolution behaviour.Consequently they have different impacts on the abundance in sediment.Dissolution continues in the periods of diagenesis,anadiagenesis and epidiagenesis.All these factors/processes interact among themselves.Our results suggest that it is necessary to consider them prudently in paleo-environmental reconstruction when using quantitative data of foraminifers